Means for oil burning



Feb. l5, 1938. J. F. sTRAlTz 2,108,621

MEANS FOR n. BURNING Filed March 3, 1954. 6 sheetsvs'neet 1 Feb. 15, 1938. J. F. sTRAxTz 2,108,621-

MEANS FoR oIL. BURNING Filed March s, 1954 e sheetsnef. 2

Feb. 15, 1938. J, F STRMTZ 2,108,621

MEANS FoR'IL BURNING Filed March s, i934 e sheets-sheet s Fel.` 15, 193s. J. F.- smmz 2,108,621

I MEANS FOR OIL BURNING Feb. 15, 1938. J. F STRAITZ 2,308,62l

MEANS FOR OIL BURNING Filed March :5, 1954 e sheets-sheet. 5v

nu. will Feb. 15, 1938. J, F, STRAITZ 2,108,621

MEANS Fork on. BURNINGl Filed March 3, 1934 6 Sheets-ShfaeiI 6 EME Srd-IZ, tow-m4 Patented Feb. l5, 1938 UNITED STATES PATE-NT OFFICE National Airoil Burner Company, Incorporated, a. corporation of Delaware Application March 3,

7 Claims.

`The invention relates to improvements in oil burning, and to improved equipment therefor.

The invention comprises improved meansv for `the eflicient atomization with primary air, of the l5 oil to be burned, and delivering thereto and thoroughly mixing therewith, in required relative amount, secondary or combustion air, all

Within the limits or bounds'of a required and controlled region.` l

in lines of travel relative to the atomized oil, best suited/to secure turbulence and thorough mixing, and also to control -the shape and dimensions of the ame.

The invention comprises a rotary atomizing cup of very gradual are or taper. This cup is substantially elongated as compared withthe present practice: For example it is nearly twice aslong as those now in common use. The ratio of flare to length of the cup in accordance with my invention is less than ten per cent, while the ratio of flare to length, in accordance with the present practice, is more than thirty per l cent.

The result of this increased length and more gradual taper or ilare, is that the oil travels an increasing number of turns in passing through the cup, which causes a greater and more even sp'read so that it is flung from the margin of the cup by centrifugal action in a much liner lm than is usual in the present practice.

This lm of oil which is flung from the margin of the cup would normally be in a plane approximately at right angles to the axis 'of the o cup,ubut, as a matter of fact, the shape of the film or the directionof the lines of its travel are modified by the action thereon of the primary air which is delivered to and tends to envelop the voil lm asit leaves the margin of the cup.

As a result, in actual practice, the lm of atomized oil as acted upon by the primary air, assumes a conical shape either long with a gradual taper or shorter With a greater taper or are, l) depending upon the control of primary air as herein described.

In addition to the modifying action of primary air upon'the oil, a further control may be provided by the delivery thereto of secondary or combustion air, all as herein described.

I provide improved means for delivering to and mingling with the oil, primary and secondary air to secure turbulence and thorough mixing and hence eiiicient combustion in the region required, and also to control or conne the com- The primary and secondary air are delivered 1934, serial No; '113,786

(ci. 15a-'m bustion of oil within the bounds of said region.

The invention includes means for creating and controlling the pressure, velocity, volume and lines of travel of the primary air, so that the same may be curved, helical or straight, and delivering said air to the lm of oil at any desired angle to the direction of travel of the oil.

The invention also includes means for de- Y livering secondary or combustion air, and means for controlling the'direction and flow of said secondary air, projected through the rire cone, or burner block, so that said secondary air currents may bedelivered to the atomized fuel in lines of travel opposed, or inclined to the lines of travel of the fuel as required.

The invention also comprises improved means for feeding the oil and controlling the volume and pressure of same, including both arbitrary and automatic controls, whereby the relation, as to -volume`and pressure, of air and oil may be adjusted and maintained to secure the required combustion conditions with respect to the type and character of furnace employed.

The invention also comprises improvements in details of construction and arrangement, thereby achieving great simplicity and maximum eiciency of operation.

VReferring to the drawings which illustrate merely by way of example, suitable means for the embodiment of my invention 30 y Fig. 1- is a longitudinal vertical section of the complete burner unit.

Fig. 2 is a plan view partly in horizontal section.

Fig. 3 is a rear elevation of the unit. 35

Fig. 4 is a longitudinal section, onI an enlarged scale, of, the air nozzle with the atomizer cup indicated in broken lines.

Fig. 5 is a rear elevation of same with vanes in one position.

Fig. 6 is a similar view with the vanes in different position.

Fig. 7 is a fragmentary cross-section of the arrangement shown in Fig. 8, except that the movable vanes are in'open position. 45

Fig. 8 is a cross-section of the air register delivering to the burner block on about the line `ll, 8 of Fig. 1, part being broken away.

Fig. 9 is a rear elevation of a burner block of refractory material such as nre-clay, on about the line 9, 9 of Fig. 1. y

Fig. 10'is a vfront elevation of same.

Fig. l1. is a section on line ll-Il of Fig. 9.

Fig. 12 is a front elevation of a burner block of heat resisting metal.

Fig. 13 is a section on line Iii- I3 of Fig. l2.

Fig. 14 is a section on line I-I of Fig. 12. Fig. 15 is a diagram indicating the scheme of oil travel or distribution.

Similar numerals refer to similar parts throughout the several views.

Referring to Fig. 1, the shaft I5 is mounted in ball bearings I6, at each end of the motor housing I'I, and carries within the housing the rotor I8 of the electric motor. To the left of the motor housing, as shown in Fig. 1,\is mounted the blower I9 having the air discharge nozzle 2U which projects through the burner block 2I of refractory material or heat resisting iron. The impeller 22, within the blower casing I9, is also mounted on and rotates with the shaft i5.

To the right of the motor housing l1, the shaft I5 is provided with the'worm 2li, meshing with the worm gear 25, mounted. on the pump shaft 2B and enclosed in the housing 2l; the normal level of the oil in housing 21 being indicated by the broken line 28.

As a feature of construction, the housing I9 of the blower, to which the air discharge nozzle 20 is attached, is hinged to the furnace fire-hole plate 29 in the usual manner to swing into and out of operating position, and is provided with a self-locking clamp 30 for normally holding it in firing position.

'I'he blower housing, the motor housing, the pump housing and the shaft-end stuing box are bolted or otherwise secured together in the order named, forming a complete unit, hinged to the re-hole plate 2S as described.

The hollow shaft I5 is entirely supported in the antifriction bearings I6, in the end walls of motor housing I'I, thus providing effective means for maintaining the exact centering of the rotor I8 which is mounted on said shaft, while the ends of the shaft which project through the bearings are sufficiently stable for the purpose; that is, at one end, for carrying and rotating the impeller 22 of the blower, and the atomizing cup 23 within the nozzle 20. At the other end, the shaft I5 carries the worm 24 cooperating with the gear 25 mounted on the pump shaft 26, al1- of which are enclosed in the housing 2l, and beyond this housing is provided the shaft-end stuffing box 3| and the various controls, regulators and indicators.`

Among the especial advantages of the arrangement of the driving and driven parts, as above described and shown in the drawings, besides stabilizing of the rotor I8 and maintaining a true concentric air gap between the rotor I8 and stator 32. are the following.

By placing the motor between the driven parts, such asthe impeller 22 and the atomizing cup 23 on one side, and the oil pump, on thetother side, the whole unit is stabilized, the stresses are balanced and vibration reduced to a minimum.

The moto; housing and the motor are placed in close proximity to the point of support of the unit, which, of course, reduces the strain to a very marked degree, as compared with present standard structures.

By placing the motor inclose proximity to the blower, as shown in Fig. 1, the air may be conducted through the motor housing and delivered directly from said housing to the blower, thus providing ideal means for maintaining the motor temperature within required limits, and, at the same time, raising the temperature of primary air delivered to the burner nozzle, which is de-4 sirable.

By the arrangement shown, the worm gear, pumphlter, heater and shaft-end stufiing box are closely associated, in a compact assembly, for delivering the oil in proper condition, tem:- perature, rate of feed, etc. to and through. the fuel tip 46; while, at the same time, all of these elements are maintained readily accessible for inspection, repair or replacement. I

'I'he primary air, drawn through the motor housing by the blower, may be controlled and adjusted by any suitable means, such for instance as the damper 33 and controlling rod 313.

The atomizing cup 23 is shown as threaded onto the shaft I5 near the discharge end thereof, and the fuel tip 45 is threaded onto the extreme discharge end of the shaft I5. This tip is provided with a suitable chamber 47 and discharge vents 48, in communication with the channel lll' in the shaft. This fuel tip 46 also serves to lock the atcmizing cup 23 more securely in position upon the shaft I5, as shown.

The atomizing cup 23, in accordance with my invention, is a distinct departure from cups of the present practice, in that it is comparatively greatly elongated and its ratio of taper or Hare is substantially reduced, as above described in the statement of invention. This results in a longer travel of the oil around the inner surface of the cup 23 from fuel tip to the discharge end. The oil is thereby thinned out and uniformly spread, and is thrown from the margin of the cup in an extremely line atomization, which makes it possible more readily to control and alter as required the dimensions and shape of the discharging lm, by the primary and secondary air discharges, in the manner to be described. 4

To this end, special forms of air projecting and air control means are provided.

The blower for primary air is of substantially standard type.

The air nozzle 20 is shown as bolted to and forming part ofthe blower housing I9. It surrounds the atomizing cup 23 almost to its discharge end, and is adapted to project a cylindrical lm of air into the film of oil, inmediately as the oil leaves the margin of the cup.

Within the nozzle 20, between its inner face and the outer surface of the atomizing cup 23, a plurality of longitudinally extending movable vanes or blades 35 are provided. (see Fig. fi) pivoted at one end to the nozzleat or near the discharge end thereof, as at 36. Said pivots are radiallyvdirected with respect to the axis of the nozzle.

The blades 35 are shaped to viii: approximately the space, in diametn'c planes, between the nozzle wall and the atomizing cup.

By proper adjustment of the blades or vener; 35, the direction of the lines of travel of the air, projected from the nozzle, is controlled. /Tne volume and velocity of flow may also be modified by said adjustment. By thus controlling the air flow from the nozzle, which tends to surround the film of oil, the general shape of the atomized oil and 'primary air may be determined. This shape is usually conical and can be changed in length and angle as desired, and consequently the shape of the "ame can be changed at will, to suit furnaces of different volumetric arrangements, for example- The opposite ends of the vanes 35 are pivotaliy connectedl by pivot elementsv 31 to a ring Il seated in a groove 35 in the rear face of the nozzle member 20. Pivots 31 extend parallel with the axis of the nozzle. This ring 38 is provided with operatingmeans suchas the lug 40, conveniently positioned for manual or automatic operation. By rotative movement of the ring, the vanes may be turned and set to any angle desired.

'Ihe wing nut 4I cooperating with the threaded post 42, secured to lug 40 and projecting through slot 43, serves to lock the ring 38 in desired position of adjustment.

By such arrangement, means are. provided, acting either independently or in cooperation with the secondary air, for changing the general shape of the yflame to suit furnaces of different volumetric arrangement, by changing the direction of flow of the projected streamsof primary air through nozzle `2li.

In a long narrow furnace, these vanes are set exactly parallel to `the axis of the cup. Thus, withthe vanes in this position a long narrow flame is obtained.

In a short wide furnace, the vanes may be adjusted to any angle that will shorten the flame and spread it to correspond with the dimensions of the combustion chamber.

In accordance with vthe now common practice, the blower is designed to discharge just suicient air, at approximately one pound per square inch pressure, to complete the atomization of the oil begun by the centrifugal action of the atomizing cup, and to project the atomized oil into the furnace. This amount, usually, is about 20% of the total air required for complete combustion; the remainder of the air for combustion being haphazardly taken into the furnace through a hole cut in the furnace wall directly below the burner. too localized, and as the chimney draft delays the union of the oil and air until both travel some distance into the furnace,-that is, the proper supply of air is prevented from coming into contact with the top of the film of atomized oilan incomplete mixture of this secondary air and. atomized oil results. Very frequently the ame is blown to the bridge-wall or to the rear of the furnace, causing pulsations. Often with this arrangement, in an endeavor to hold the flame at the nozzle and to prevent pulsation, an excess amount of air, over that required, is introduced for example, through an opening made in the furnace wall. This makeshift arrangement does prevent the flame from being blown away from the atomizing cup, where it should begin, but does not improve the eiciency of combustion for the reason that too much air is delivered at improper points and in an improper manner.

One of the objects of the present invention is to provide means for eliminating this difficulty; to obtain more perfect control of the air-oil mixture by introducing the secondary air as a cylindrical lm which completely surrounds the atomized oil, and, by giving a rotary motion to this air. 'I'his motion beginning directly before coming into the zone from which the oil is iiung from the cup, causes a rotary turbulence to take place immediately from the edge of the nozzle 20. Thus more intimate and much morerapid contact between air and oil is obtained, thereby permitting complete combustion with less excess of air.

To this end my invention also comprises improved secondary air delivering means; for example I have provided an air controlling register, in conjunction with a refractory burner block,

As this methody of air introduction isor a heat resisting metallic burner block. These blocks are provided with vanes adaptedy to give a helical direction to the flow of air.

In Fig. 8, I showin cross-section such a reg`- ister adapted. to deliver directly to the burner block 2|. A number of stationary curved vanes directed and equally or symmetrically spaced as shown, with their outer edges terminating at the periphery of the register. Between these outer edges of the vanes are pivotally mounted a corresponding number of shorter vanes, or shutters 5I having approximately the same curvature as the stationaryvanes 50. These movable vanes 5| are so proportioned and mounted that when in open position, as shown in Fig. 7, they are substantially parallel with the stationary vanes between which they project, and when in closed position, as shown in Fig, 8, they underlap one adjacent end and overlap the 'other adjacent end of the stationary vanes, and thus present an approximately cylindrical wall or periphery.

It will be obvious that when the shuttersf5| are in the open position, as shown in Fig. 7, they will cooperate with the stationary vanes 50 in imparting a rotative or whirling movement to moved into closed, or open, or intermediate positions of adjustment as required.

This register may be .adapted to operate as a natural draft register, operating by natural draft of the stack, or other means for inducing ai'r therethough, in which case the air may enter the register directly from the boiler room.

Or the register may operate in conjunction y with a wind-box, indicated by the reference numera] 55.

As above stated, by the introduction of secon-dary air through Aopenings cut in the furnace wall above and below the burner, due to the pull of the draft, the air does not meet with the upper portions of the oil spray from the atomizing cup, until the oil travels some distance from the cup, and further, as the air travels in the same general direction as the oil, little time is givenl for the air thoroughly to wipe each globule of atomizedoil. As a consequence, there is a deficiency of air from the point at which theV oil leaves the atomizing cup to the point where the secondary air sweeps up and meets the oil spray, and an over-abundance of it from this point on. This results in poor mixing of air and oil, and in the usual condition of high CO and CO2 losses.

This condition is eliminated by the means in accordance .with the present invention. With the radially extending curved .vanes of the register,

Y5l! are positioned within the register, radially cess of air very close to that theoretically required.

The increase in efficiency due to better atomization and mixing of air and oil, is also further enhanced by the arrangement made for the control of the movable vanes across the gaps made by the spacing of the stationary vanes. This is done, as above described by a manual or automatic operation of a concentrically positioned master gear which meshes with the segment gears attached to each movable vane.

As a further improvement of the secondary air delivering means, I provide the spiral vane burner-block 2|, of refractory material, which projects beyond the furnace wall into the cornbustion chamber as shown in Figs. 1, 2, 9 to 11 inclusive, or of heat resisting metal as shown in Figs. 12 to 14 inclusive, which gives a rotary motion to the air delivered therethrough.

The vanes of these blocks 2l are radially curved as shown in Figs. 9, 10 and 12, and are also axially inclined as shown in Figs. 11 and 14. The chief advantage of the block of heat resisting iron, is that it can be used at high capacities due to the fact that the thickness of the vanes may be less than in the refractory block, thus giving passages of greater area for air flow.

This burner-block is preferably used in conjunction with the cylindrical register, in which case such burner-block serves to cooperate with and increase the rotary motion imparted to the air by the curved vanes of the register. This secondary air by its rotary motion is directed to and tends to envelop and ihtermix with the atomized oil and primary air, and causes this movement to continue into the furnace thereby creating turbulence.

Theenveloping and intermixing secondary air also tends to determine the extent and shape of the body of oil and primary air within theA furnace.

The means for delivering secondary air as above described, also serves the extremely important purpose of protecting the register and rotary burner unit from the radiant heat of combustion.

Referring especially to the diagram Fig. l5, the oil delivers through pipe 58, from a supply tank $9, and is drawn through the suction strainer 69 by the usual pump 60, whence it passes to pipe 6i provided with the pressure relief valve 62. The oil passing through the relief valve is returned through pipe 63 to the supply tank. 'I'he oil not passing through the relief valve, is delivered under the pressure maintained by the relief valve, to the heater 64, and thence to and through the magnetic shut-off valve 65, to and through the high-low control valve 66, provided with the pres` sure gage 66',v thence through the micrometer metering oil regulating valve 67, and thence to and through the channel l5' of shaft I5 to and through the fuel tip 46. 'I'he pressure of the oil delivered to the channel l5 of shaft I5, is primarily controlled by the adjustable relief valve ilsubject to the further controls of valves 65,. 66 and $1.

. Operation gin of the cup at approximately right angles to the axis of the cup. To this fuel film is delivered an approximately cylindrical film of primary air from nozzle 20. The surrounding primary air impinges on the fuel instantly as the fuel leaves the margin of the cup. By means of the vanes in the air nozzle 20, this surrounding primary air may be directed in a helical direction, so that the lines of travel of the fuel film will be modified and the shape and bounds of the combined atomiz'ed fuel and air changed as required. By having the primary air impinge upon the fuel the instant it leaves the cup margin, and by controlling the volume, velocity and direction of ow of the air, turbulence is created between each globule of atomized oil, thus greatly adding..

to the emciency of atomization and combustion.

The operation above described, is rendered still more effective, and subject to arbitrary or automatic control by the action of secondary air delivered through the register and the burner-block or diHuser ring 2i.

This secondary air is delivered to the primary air and fuel shortly after the same have been brought together and have begun a turbulent intermixing. x

By controlling the direction of travel of secondary air, which may also be helical or rotary, a further modification of the coaction oi the fuel, primary air and secondary air, is secured.

In other words, by controlling the pressure, volume and velocity of oil delivered to and through the channel I5', by controlling the pressure, volurne, velocity and direction of travel of the primary air, and also of the secondary air, all relative to the `speed of rotation of the atomizing cup, flames may be produced to suit furnaces of diiferent volumetric arrangements. That is the flame may be made and maintained with volumetric bounds to suit the type of combustion chamber of the particular furnace to which it is to be applied. And also, with such arrangement and control, the maximum efficiency oi' combustion and heat transfer is secured.

By interconnecting the controls, or certain of them, the conditions may be automatically maintained within required limits while meeting variation or fluctuation in the demands upon the furnace.

What I claim is:-

1. In an oil burning system, the combination of a rotating atomizing cup and a nozzle for primary air surrounding the cup, an annular member rotatably seated in the rear wall of the nozzle, air deflecting vanes co-extensive with the nozzle and the cup and interposed between said nozzle and cup, said vanes pivoted in the wall of the nozzle at the discharge end thereof, and pivoted at their rear ends to said annular member.

2. In an oil burning system, the vcombination of a rotating atomizing cup and a nozzle for primary air surrounding the cup, a burner block formed of heat resisting material surrounding the discharge end of the primary air nozzle and provided with helical channels for secondary air and an air register having adjustable controls for delivering secondary air to said channels.

3. In an oil burning system, the combination of a rotating atomizing cup and a nozzle for primary air surrounding the cup, a burner block formed of heat resisting material surrounding the discharge end of the primary air nozzle and provided with helical channels for secondary air, and an air register for delivering secondary air to said channels, said register including evenly spaced radiating curved vanes, and adjustable air shutters arranged around the periphery of the register in arcs of circles corresponding to the arcs of the curvedvanes, so that when in open position the shutters cooperatel with the vane's and said channels in imparting a whirling motion toV the secondary air passing therethrough.I

4. In an oil burning device, the combination of a rotatable oil atomizing cup, a nozzle member for primary air surrounding and substantially coextensive with the cup, an annular member rotatably associated with the rear end of the nozzle member, and adjustable air deflecting vanes, interposed between and coextensive with the nozzle member and cup, supported at the front end of the nozzle member on radially extending pivots, and at the rear end of the nozzle member on pivots extending parallel with the axis of the cup, and connected to the annular member.

5. In an oil burning device, the combination of a rotatable oil atomizing cup, a nozzle member for primary air surrounding and approximately lcoextensive with the cup, a burner block of heatresisting material surrounding the nozzle member and provided with helical passages for secondaryair, and an air register delivering to the burner block, said register having radially directed curved vanes, and peripherally arranged adjustable shutters of curvature corresponding to the curvature of the radially directed vanes, said curved varies and shutters adapted to cooperate with the inclined helical passages of the burner block, to give a helical direction of travel to the secondary air. y

6. In an oil burning system, the combination of a rotating atomizing cup and a nozzle for admission of primary air surrounding the cup, a burner block surrounding the primary air nozzle, said block comprising an annular rim, an annular hub and radially extending curved vanes connecting the rim and hub and forming helical passages for admission of secondary air around said primary air nozzle.

'7.4 In an oil burning system, the combination of a rotating atomizing cup and a. nozzle for admission of primary air surrounding the cup, a burner block surrounding the primary airnozzle, said block comprising an annular rim, an/annular hub and radially extending curved vanes connecting the rim and hub and Vforming helical passages for admission of secondary air around said primary air nozzle, the delivery end of the cup projecting beyond the delivery end of the nozzle, the delivery end of the nozzle projecting beyond the adjacent front margin of the hub, and the front face of the rim projecting beyond the delivery end of thenozzle.

JOHN F. S'I'RAITZ. 

